Rob Wormald recognized that we had no plunker for a simple component test. Inspired improved learning path for testing including:
* Add plunkers for both inline and external template versions of the simplest `BannerComponent`
* Added the banner-specs for that purpose and also a quickstart-specs in the setup folder
* Adjusted prose in testing and setup-systemjs-anatomy to call these out
* Moved testing of external template spec earlier in the guide because it is likely to be needed right away.
* Add comments on the optional "testing" folder and corrects var names to match
* Leaves Jasmine Spec Runner output visible when tests finish
* plunker builder removes files and scripts not needed in plunkers (e.g., systemjs.config.js)
* no longer adds placeholder README.md (deemed a distraction)
* tag is now "Angular" instead of "Angular2"
* new plnkr.json "includeSystemConfig" option adds systemjs.config.js back; needed for testing plnkrs.
* incidentally changes comment "Polyfill(s)" to "Polyfills" in all index.html
Jesús Rodríguez
Filipe Silva
Ward Bell